decoders.hpp

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//
// Created by ColorsWind on 2022/5/18.
//
#pragma once
 
#include "helper.hpp"
INCLUDE_FFMPEG_BEGIN
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libavutil/error.h>
#include <libswresample/swresample.h>
#include <libavutil/imgutils.h>
INCLUDE_FFMPEG_END
#include <QDebug>
#include "frame.hpp"
#include "twins_queue.hpp"
#include "concurrentqueue.h"
#include "audioformat.hpp"
#include <atomic>
#include <utility>
 
class IDemuxDecoder {
 
public:
    enum class DecoderType {
        Audio,  
        Video,  
        Common, 
    };
    virtual bool accept(AVPacket *pkt, std::atomic<bool> &interrupt) = 0;
 
    virtual void flushFFmpegBuffers() = 0;
 
 
    virtual VideoFrameRef getPicture() = 0;
 
    virtual AudioFrame getSample() = 0;
 
    virtual qreal viewFront() = 0;
 
    virtual int skip(const std::function<bool(qreal)> &predicate) = 0;
 
    virtual double duration() = 0;
 
 
    virtual void setEnable(bool b) = 0;
 
    virtual ~IDemuxDecoder() = default;
 
    virtual void setFollower(IDemuxDecoder* follower) {NOT_IMPLEMENT_YET}
 
    virtual void pushFrameStack() {}
 
    virtual qreal getLastPts() {
        NOT_IMPLEMENT_YET
    }
 
    virtual void clearFrameStack() {}
 
    virtual void setStart(qreal secs) {}
 
    virtual qreal nextSegment() {
        NOT_IMPLEMENT_YET
    }
 
    virtual PonyAudioFormat getInputFormat() = 0;
 
    virtual void setOutputFormat(const PonyAudioFormat& format) = 0;
};
 
class DecoderContext {
public:
    AVCodec *codec = nullptr;
    AVStream *stream = nullptr;
    AVCodecContext *codecCtx = nullptr;
    AVFrame *frameBuf = nullptr;
    DecoderContext(AVStream *vs): stream(vs) {
        auto *videoCodecPara = stream->codecpar;
        if (!(codec = const_cast<AVCodec *>(avcodec_find_decoder(videoCodecPara->codec_id)))) {
            throw std::runtime_error("Cannot find valid video decode codec.");
        }
        if (!(codecCtx = avcodec_alloc_context3(codec))) {
            throw std::runtime_error("Cannot find valid video decode codec context.");
        }
        if (avcodec_parameters_to_context(codecCtx, videoCodecPara) < 0) {
            throw std::runtime_error("Cannot initialize videoCodecCtx.");
        }
        if (avcodec_open2(codecCtx, codec, nullptr) < 0) {
            throw std::runtime_error("Cannot open codec.");
        }
        if (!(frameBuf = av_frame_alloc())) {
            throw std::runtime_error("Cannot alloc frame buf.");
        }
    }
 
    ~DecoderContext() {
        if (frameBuf) { av_frame_free(&frameBuf); }
        if (codecCtx) { avcodec_close(codecCtx); }
        if (codecCtx) { avcodec_free_context(&codecCtx); }
    }
 
};
 
 
constexpr auto Audio  =  IDemuxDecoder::DecoderType::Audio;
constexpr auto Video  =  IDemuxDecoder::DecoderType::Video;
constexpr auto Common =  IDemuxDecoder::DecoderType::Common;